RHEL 7 vs RHEL 6
Red Hat Enterprise Linux 7 is an Light weight and minimized Operating system. RHEL 7 changes are huge effect to enterprise.Let's see what changed in RHEL 7 as per administration prospective.
- First one is Anaconda Installer Completely new.
- Grub version updated from 0.97 to Grub 2 fast booting
- Procedure of bypassing root password at booting process completely different than RHEL 6/5
- There is no SysV Initd in RHEL 7 it's an new Systemd
- Run Levels are changed to Targets.
- Default file system in RHEL 7 is XFS. XFS file system supports 550TB of each partition size in 64-bit.
- Directories /bin /sbin /lib and /lib64 are moved under /usr/
- Network Interface Names are changed from eth0 to ens.xxx
- New concept to create multiple profiles top of one Ethernet card, No need of changing IP addresses and settings every time when you connect different networks, simply activate different profile.
- GNOME version changed from 2 to 3
- No classic registration system, completely changed to Red Hat subscription Manager
- Default database is MariaDB instead of MySQL
- Cluster Manager has been changed to Pacemaker and Corosync
- Ifconfig command is deprecated, replaced with ip command
- User Identification Numbers (UID's) changed from 500 to 1000, which means when you create new normal user in RHEL 7 will get UID from 1000 to 65534
- locate command is changed to mlocate
- yum commands are changed little bit
| Feature Name | RHEL 6 | RHEL 7 |
| Default File System | Ext4 | XFS |
| Kernel Version | 2.6.xx | 3.10.xx |
| Release Name | Santiago | Maipo |
| Gnome Version | GNOME 2 | GNOME 3.8 |
| KDE Version | 4.6 | 4.1 |
| Release Date | 10-Nov-10 | 10-Jun-14 |
| NFS Version | NFS 4 | NFS 4.1. NFS V2 is deprecated in RHEL 7 |
| Samba Version | 3.6 | 4.4 |
| Default Database | MariaDB | MySQL |
| Cluster Resource Manager | Rgmanager | Pacemaker |
| Network Grouping | Team Driver will support multiple types of Teaming methods called Active-Backup, Load-balancing and Broadcase | Bonding can be done as Active-Backup, XOR, IEEE and Loac Balancing |
| KDUMP | RHEL 7 can be supported up to 3TB | Kdump does't support with large RAM Size |
| Boot Loader | Grub
2 /boot/grub2/grub.cfg |
Grub
0.97 /boot/grub/grub.conf |
| File System Check | xfs_replair
- Inode blockmap checks -Inode allocation map checks -Inode size check -Directory check -Path Name check -Link count check -Freemap check -Super block check |
e2fsck -Inode check. Block and size check --Directory Structure check -Directory Link Check -reference count check -Group Summary Check |
| Process ID | Systemd (1) | Initd (1) |
| Port Security | Firewalld instead of iptables. Iptables can also support with RHEL 7, but we can't use both of them at the same time. Firewall will not allow any port until and unless you enabled it. | iptables by default service port is enabled when service is switched on. |
| Boot Time | 40 Sec | 20 Sec |
| File System Size | EXT4 16TB with XFS 100TB | XFS 500TB with EXT4 16TB |
| Processor Architecture | 32Bit and 64Bit | Only 64Bit. |
| Network Configuration Tool | steup | nmtui |
| Hostname Config File | /etc/sysconfig/network | /etc/hostname No need to edit hostname file to write permanent hostname simply use hostnamectl command |
| Interface Name | eth0 | ens33xxx |
| Managing Services | service
sshd start service sshd restart chkconfig sshd on |
systemctl
start sshd.service systemctl restart sshd.service systemctl enable sshd.service |
| System Logs | /var/log/ | /var/log journalctl |
| Run Levels | runlevel
0 - Power Off runlevel 1 - Single User Mode runlevel 2 - Multi User without Networking runlevel 3 - Multi User CLI runlevel 4 - Not USed runlevel 5 - GUI Mode runlevel 6 - Restart |
There
is no run levels in RHEL 6. Run levels are called as targets Poweroff.target rescue.target multi-user.target graphical.target reboot.target |
| UID Information | Normal
User UID will start from 500 to 65534 System Users UID will start from 1 to 499 |
Normal
User UID start from 1000 - 65534 System Users UID will start from 1 to 999 Because Services are increased compare to RHEL 6 |
| By Pass Root Password Prompt | append 1 or s or init=/bin/bash to Kernel command line | Append rd.break or init=/bin/bash to kernel command line |
| Rebooting and Poweroff | poweroff
- init 0 reboot - init 6 |
systemctl
poweroff systemctl reboot |
| YUM Commands | yum
groupinstall yum groupinfo |
yum
group install yum group info |
Thanks, please provide your valuable feedback on the same.